﻿using System;

namespace ConsoleApp17
{
    class Program
    {
        static void Main(string[] args)
        {
            int count = 0;//计数器
            int sum = 0;//求和

            while (true)
            {
                Console.Write("请输入成绩(输入-1结束):");
                int cj = int.Parse(Console.ReadLine());

                if (cj == -1)
                {
                    break;
                }
                else
                {
                    sum += cj;
                    count++;
                }
                
            }


            Console.WriteLine("平均数为" + sum / count);

            Console.ReadKey();
        }
    }
}
